In recent years, mobile phones have been remarkably widespread. One of the factors resides in that the popularity of camera-equipped mobile phones has increased.
The camera-equipped mobile phones are literally mobile phones with a camera. The camera of the camera-equipped mobile phone is designed in such a manner that imaging means that is normally a charge coupled device (CCD) is incorporated into a common case of the mobile phone, and a camera lens that guides an image light to the imaging means is mounted at a given position of the case in such a state that the camera lens is exposed from the case.
The camera-equipped mobile phone is configured as described above to carry out photography.
The camera-equipped mobile phone has a function of making photography easier by an aid of the mobile phone that is frequently carried. The camera-equipped mobile phone also has a function, which is not provided to the conventional cameras, of attaching a picture that has been taken by the camera-equipped mobile phone to an electronic mail that is realized by an electronic mail function of the mobile phone so as to be transmitted to another mobile phone without the aid of another device in many cases. Those characteristic functions are to provide new pleasure that is not supplied by the conventional camera.
With the above-mentioned characteristic function, the camera-equipped mobile phone succeeds in stimulating a sense of fun of a user, and has been widely widespread among people who frequently take a picture, in particular, young people.
In view of the above-mentioned circumstances, in order to further spread the camera-equipped mobile phones, it can be understood that something to further stimulate a sense of fun of the user is required.
Taking this point into consideration, a study for providing the camera-equipped mobile phone with a function of further stimulating the sense of fun of the user has been conducted.
For example, an image that can be taken by the camera-equipped mobile phone had been only a still image before, but a moving image or a frame-by-frame advance image can be now also taken. Also, recent camera-equipped mobile phones have a function of storing a given image in a memory that is incorporated into the camera-equipped mobile phone in advance, and then combining the stored image with an image that has been taken by the camera-equipped mobile phone.
One measure for stimulating the sense of fun of the user is to change the image that can be taken by the camera-equipped mobile phone. One of the simplest changes is to increase the magnification of the image that can be taken.
When the image having a magnification as in a telescope or a microscope can be taken, the camera-equipped mobile phone becomes a telescope or a microscope which can be easily carried, and it is assumed that the application thereof is different from that of the conventional mobile phones.
However, it is not so easy for the camera-equipped mobile phone to take the image with high magnification.
In general, a camera provided to the camera-equipped mobile phone is equipped with a lens having a viewing angle (in general, 60° to 70°) which is considered to be relatively “wide angle” among tenses provided to the cameras to enable taking an image of a person or a scene which is a main application thereof easily.
When an image light enters the above-mentioned lens having the wide viewing angle through an objective lens that is generally a magnifying lens, an area into which no image light is introduced appears in a part of the viewing angle of the lens of the camera provided to the camera-equipped mobile phone. This part is displayed as black in a final image because the image light is not introduced into the part, and as a result, the final image has a black bordering. In other words, an appropriate imaging cannot be conducted when the objective lens is merely disposed in front of the lens of the camera of the camera-equipped mobile phone.
Also, even in the case where the camera of the camera-equipped mobile phone is used as a microscope, it is necessary to deepen the focal depth in order to facilitate the focusing of a focal point on an object to be imaged, which also applies to the conventional microscope. In this case, it is necessary to narrow the image light from the object to be imaged by an aperture. In this case, a solid angle of the light that enters the lens of the camera of the camera-equipped mobile phone through the objective lens becomes small. Therefore, there tends to arise such a problem that the black region appears in the final image as described above, particularly in the case where the camera of the camera-equipped mobile phone is used as the microscope.
Even if the objective lens is added to a camera having a fixed lens other than the camera-equipped mobile phone to take a picture, the above-mentioned phenomenon that nothing other than the image partially having the black part can be imaged can occur as well.
That is, in the case where another objective lens is additionally disposed in front of the lens that is incorporated into the existing camera to take an image whose magnification is generally increased, the above-mentioned problem that images other than the image partially having the black part (generally having the black bordering) cannot be taken by merely introducing the image light that has passed through the object lens to the lens that is originally provided to the camera arises not only in the camera-equipped mobile phone, but also in the conventional cameras.
An object of the present invention is to provide a magnifying attachment for allowing a camera which includes a camera provided in the camera-equipped mobile phone to take an image at a magnification higher than a magnification at which the camera can originally take an image, which takes an image including no black part where no image can be seen.